Experts in reproductive health from the UK advise women who are preparing to conceive to avoid consuming a lot of soy-based foods.
After conducting research on humans, scientists discovered that a compound in soy called genistein can destroy sperm before they can fertilize an egg.
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Professor Lynn Fraser |
Professor Lynn Fraser from King’s College London stated that even a small amount of this compound is enough to kill sperm.
In her speech at the European Society of Human Reproduction, Lynn said: When preparing for pregnancy, women should avoid eating foods containing soy to facilitate the fertilization process.
The genistein compound is found in all soy products such as soy milk, vegetarian foods, and other items.
In her experiment, Professor Fraser tested the effects of genistein on sperm when they were allowed to interact in a petri dish.
This compound triggers a reaction in most sperm, reducing their ability to fertilize an egg.
However, in reality, this phenomenon usually only occurs when sperm have been inside a woman’s body for several hours and are preparing to fertilize an egg.
For this reason, if genistein appears in a woman’s uterus, sperm will be weakened too early before they can fertilize the egg. This also means that the process of conception will not be able to take place.
Professor Fraser found that the amount of genistein needed to cause this reaction in humans is much lower compared to mice. She said: “We were very surprised to find that human sperm reacted more readily to genistein than sperm from mice. Up until now, we haven’t been able to accurately determine the amount of soy that women can safely consume, but it is best for them to stop using these products a few days before they might conceive.”
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| Soy contains a compound called genistein that will destroy sperm before they can fertilize an egg. (Photo: uky.edu) |
In a previous experiment on mice, Professor Fraser found that some compounds similar to genistein in certain hop-based products like beer also affect sperm in a similar manner.
These compounds are weak estrogens, but according to the professor, their effect on sperm is not like female sex hormones; rather, genistein seems to stimulate the production of a signaling molecule in sperm known as AMP.
Dr. Allan Pacey, a senior lecturer at the University of Sheffield, stated: “Although these are just preliminary tests, if what happens in the lab also occurs in the fallopian tubes of women when sperm are preparing to fertilize, the risk of this process failing is very high.”
A spokesperson for the Vegetarian Society also shared their perspective: “For women preparing to conceive, it is advisable to stop using soy products for a few days. Indeed, most vegetarians use these products in their meals, but there are plenty of alternative products available, so there should be no issues.”
